Halide Perovskite Lasers

Description

This book highlights the rapidly emerging field of solution-processed halide perovskite lasers. These amazing materials not only possess exceptional photovoltaic properties, but are also outstanding optical gain media. Halide perovskites are the latest member of solution-processed optical gain media, joining organics and traditional semiconductor colloidal quantum dots. Amplified spontaneous emission and lasing have been demonstrated in various halide perovskite configurations and nanostructures with wavelengths tunable over the visible and infrared wavelengths (400–1000 nm). This book provides comprehensive information on perovskite lasing, starting with some fundamentals of lasers and their basic operating principles. Unambiguous methods for identifying lasing light emission are presented, while the basic optoelectronic properties of perovskite materials are also discussed, with an emphasis on their photophysics, using ultrafast optical spectroscopy techniques. The viability of perovskites as a gain media within a suitable resonator, as well as the characterization methods for optical gain, are highlighted. The book closes with a discussion on the remaining challenges (such as electrical driven lasing and material stabilities) that need to be tackled, and the future of this new family of lasers. Preface Contents 1 Introduction: Fundamentals of Lasers 1.1 What is a Laser? 1.2 The Gain Medium 1.2.1 Radiative Transition Rates and Einstein’s Relations 1.2.2 Population Inversion in Two, Three and Four-Level Systems 1.2.3 The Gain Coefficient and Gain Saturation 1.2.4 Amplified Spontaneous Emission 1.3 Laser Oscillations: Gain Medium with Optical Feedback 1.3.1 Cavity Modes and Lasing Modes 1.3.2 Steady-State Laser Oscillations and Gain Threshold Conditions 1.3.3 Figures of Merit: Q-Factor and Finesse 1.4 Characteristics of Lasers 1.4.1 Differentiating Amplified Spontaneous Emission and Lasing 1.5 Summary and Conclusions References 2 The Halide Perovskite Gain Media 2.1 Introduction to Halide Perovskites 2.1.1 The Perovskite Crystal Structure 2.1.2 Perovskite Structural Tuning 2.1.3 Research Interests in Perovskite Lasers 2.2 Optical Gain in Perovskite Morphologies 2.2.1 Perovskite Single Crystals 2.2.2 Perovskite Thin-Films 2.2.3 Perovskite Micro- and Nanoplatelets (PMPLs and PNPLs) 2.2.4 Perovskite Micro- and Nanowires (PMWs and PNWs) 2.2.5 Perovskite Micro- and Nanocrystals (PMCs and PNCs) 2.3 Summary and Conclusion References 3 Optical Gain Mechanisms and Fabrication of Perovskite Lasers 3.1 Optical Gain Mechanisms in Halide Perovskites 3.1.1 Spectroscopic Tools for Studying Optical Gain 3.1.2 Free-Carrier Optical Gain 3.1.3 Biexciton Optical Gain 3.1.4 Trion Optical Gain 3.1.5 Single Exciton Optical Gain 3.1.6 Polariton Optical Gain 3.2 Fabrication Techniques for Perovskite Lasers 3.2.1 Fabry–Perot Perovskite Lasers 3.2.2 Whispering Gallery Mode (WGM) Perovskite Lasers 3.2.3 Distributed FeedBack (DFB) Perovskite Lasers 3.2.4 Perovskite Random Lasers 3.3 Summary and Conclusions References 4 Outlook and Conclusions 4.1 General Conclusions 4.2 Remaining Challenges of Perovskite Lasers 4.2.1 Toxicity of Lead Halide Perovskite Based Lasers 4.2.2 Electrically Pumped Perovskite Lasing: Device and Thermal Managements 4.3 Concluding Remarks References